CN116324264A

CN116324264A - Insulation tank with integrated or operably connected support system

Info

Publication number: CN116324264A
Application number: CN202180054674.8A
Authority: CN
Inventors: 帕尔·G·贝甘
Original assignee: Letis International Ag
Current assignee: Letis International Ag
Priority date: 2020-09-04
Filing date: 2021-09-03
Publication date: 2023-06-23
Also published as: EP4208666A1; JP2023541001A; AU2021336470A1; WO2022050849A1; US20230324005A1; NO346581B1; NO20200965A1; KR20230062580A

Abstract

The present invention meets the object by providing an insulated tank system comprising: an inner tank; a thermal insulator outside the inner vessel; an inlet and outlet from the exterior of the tank to the interior of the inner tank or a combined inlet and outlet for filling and emptying the fluid, wherein the inner tank contains the fluid in operation. The tank system is distinguished in that it further comprises thermal insulation in the form of insulation block elements arranged externally side by side on the inner tank, with a gap between the insulation block elements at least on their outer sides, wherein the tank system further comprises a support structure comprising one or more block elements, wherein each block element faces and is in contact with the insulation block elements directly or via one or more intermediate layers, wherein the support structure comprises a structure for lifting the tank by the support structure, wherein the tank can be lifted and handled by loading only the outer insulation block elements facing said block elements without directly loading the inner tank, and wherein thermal shrinkage or expansion is absorbed by the gap between the block insulation elements.

Description

Insulation tank with integrated or operably connected support system

Technical Field

The present invention relates to a system or apparatus for handling tanks for storing and transporting fluids. More particularly, the present invention provides an insulated tank having an integrated or operably connected support system that is particularly suited for large cryogenic tanks, and a method of manufacturing and installing a tank having an insulation.

Background

Safe storage and handling of fluid-containing tanks can be critical to safety, health, and environment. Many fluids are preferably stored and transported at temperatures well below or well above ambient temperature. Insulated tanks for storing and transporting cryogenic fluids, such as liquid hydrogen, are one example of tanks where leakage is unacceptable.

Specific load conditions on an externally insulated tank may come from the manufacturing stage (such as assembly, lifting, transportation and installation) and the working stage of the tank, where the load may be caused by: variable temperature, variable pressure and variable cargo weight, and inertial loads caused by movement of the vehicle or vessel on which the tank is mounted. Good design of such loads is critical to the safety of personnel, environment and assets. This is especially true when damage can lead to explosive, flammable, toxic, or very hot or very cold fluid leaks.

The fluid is contained in a tank structure suitable for the purpose of meeting all safety and regulatory requirements related to deformation, strength, stability and fatigue integrity under suitable load and thermal conditions. A particular challenge for tanks containing fluids at temperatures very different from the initial tank conditions and the surrounding environment is that the overall size and shape (e.g., radius of curvature) of the tank will vary depending on the thermal characteristics of the tank (secant coefficient dependent on thermal expansion/contraction). This geometrical variation generally affects the way the tank should be supported in order to avoid incompatible and severe stresses on the tank and on the supporting structure and, ultimately, on the base on which the tank rests. This interaction problem becomes more serious when the tank is covered on the outside with a light and weakly insulating material.

For some insulation cans, the secondary containment structure is disposed outside of the thermal insulation, with the outer shell protecting the insulation. Obviously, the thermal contraction (or expansion) of the inner vessel has an effect on the outer shell, depending on the way the two layers are connected and the way the outer shell is designed. In a simple case, the outer protective shell for thermal insulation is a corrugated sheet or "skin" which can be adapted to the thermal deformation of the inner tank. Tanks, such as stand alone tanks for Liquefied Natural Gas (LNG) at-163 ℃, are typically supported on fixed and sliding blocks of wood or plastic that will provide contact between the inner tank and a base at outside ambient temperature. This results in a so-called "thermal bridge", which means an increase in heat ingress, which can lead to an undesirable increase in temperature and pressure in the contained fluid if the boil-off gas resulting from the heat ingress is not discharged from the tank.

Some cryogenic tank applications may require additional high performance thermal insulation. In a sense, vacuum isolation provides an ideal solution because the ideal vacuum prevents heat from entering through heat conduction and convection. Furthermore, vacuum-type insulation may be the only acceptable method of containing a fluid, such as liquid hydrogen (LH 2) at about-253 ℃. Conventional load lock tanks are designed as double wall tanks, wherein an outer shell or "jacket" should be designed to carry the pressure difference between atmospheric pressure and near vacuum conditions in a layer between the two shells. Such cans present a series of challenges related to the thermal bridge that should be connected between the two shells, the fact that the outer shells are subjected to external pressures that can cause instability and buckling, and the significant dimensional differences and incompatibilities between the two structural layers caused by the thermal shrinkage of the inner can. For these reasons, vacuum insulation has heretofore been applied to cans of limited size (e.g., hundreds of cubic meters).

It is an object of the present invention to provide a tank or tank system, use and method thereof that is beneficial for one or more of the challenges described above.

Summary of The Invention

The present invention meets this object by providing an insulated tank or tank system comprising: an inner tank; a thermal insulator outside the inner vessel; an inlet and outlet from the exterior of the tank to the interior of the inner tank or a combined inlet and outlet for filling and emptying the fluid, wherein the inner tank contains the fluid in operation. The tank system differs in that it further comprises:

thermal insulation in the form of insulation block elements arranged side by side on the outside on an inner vessel, with a gap between the insulation block elements at least on their outer sides, wherein the vessel system further comprises a support structure comprising one or more block elements (also referred to as support block elements, soft support elements or soft supports), wherein each such block element faces and is in contact with a respective insulation block element directly or via one or more intermediate layers, wherein the support structure comprises a structure for lifting the vessel by the support structure, wherein the vessel can be lifted and handled by loading only the outer insulation block elements facing said block elements and not directly the attachment to the inner vessel, and wherein thermal shrinkage or expansion is absorbed by the gap between the block insulation elements.

The insulated tank system of the present invention facilitates manufacturing, shipping, installation and certification of the tank without limiting the maximum size of the tank. The inlet and outlet, alone or in combination, from the exterior of the tank to the interior of the inner tank is the only structure that penetrates the insulation and provides a significant thermal bridge. The inner tank is preferably a pressure tank allowing a pressure as high as at least 5 bar, 15 bar or 20 bar. No lifting lugs or other similar structures are required and therefore no lifting lugs need to be removed after installation, thus simplifying testing and certification of the tank system.

The dependent claims define preferred embodiments of the tank system of the invention.

The invention also provides a method of manufacturing a tank according to the invention. The method differs in that, at the place of manufacture or in the vessel,

the manufacturing or provision of an inner vessel, preferably a pressure vessel,

the insulating block elements are arranged side by side on the inner vessel, with gaps between the insulating block elements,

the inlet and outlet are manufactured or provided as a combined structure or as separate structures,

a hermetically sealed outer housing structure is manufactured or provided, which, if a vacuum pump is included in the tank embodiment, has a coupling for the vacuum pump,

at least one support structure is manufactured or provided for operative construction or connection to the tank, wherein the support structure comprises one or more block elements, each block element having a shape matching a specific insulating block element, wherein the support structure comprises a structure for lifting the tank by the support structure, thereby allowing lifting and transporting of the tank in a manner that does not directly load the inner tank.

Preferred embodiments are defined in the dependent claims.

Further preferred embodiments and features will be apparent to those skilled in the art from the detailed description and the illustrative embodiments.

In the context of the present invention, a support structure particularly refers to a structure on which a can may rest in such a way that by resting an outer surface section of the can on an upper surface of the support structure that matches the shape of the outer surface section of the can, wherein said upper surface of the support structure has a flat shape, a curved shape, a doubly curved shape or a shape comprising a combination thereof corresponding to the outer surface of the can in a contact area, wherein the contact area is sufficiently large to ensure that the strain and stress at any point in the contact area remains below a safety limit.

In the context of the present invention, a definition of a safe stress limit is that the maximum stress at any point in the contact area between the tank and the bulk element does not exceed the allowable limit defined in international gas regulations (IGC and IGF for fuel tanks) and in regulations for pressure tanks according to ASME. For example, the maximum stress does not exceed a requirement regarding von mises yield criteria or a portion thereof is one example of a safety limit.

The soft support concept of the present invention in combination with a block insulation system for tanks (with lateral supports as required) provides significant advantages with respect to the manufacture, transportation and installation of insulation tanks. More specifically, when lifting a tank of the present invention, optionally with soft supports and possibly also with lateral supports, by arranging the lifting cords to the support structure, the surface area of the insulation for carrying the load of the tank can be used for lifting without unduly stressing the insulation and the structure. No lifting lugs are required for attachment to the inner vessel, which can create a thermal bridge through the insulation, or which must be cut off after installation and the insulation repaired. Thus, no thermal bridge needs to be introduced, no lifting lugs are needed, and no lifting lugs need to be removed, as the stress level has become insignificant. In addition to performing overall system testing of the connecting piping and the like, there may be no need to retest and/or re-certify the tank container structure after it has been installed in its intended operating position. The combined contact area between the support block element and the insulation can should be large enough to ensure that the acceptable stress at any point is below any critical limit specified by regulatory rules and regulations. If desired, the insulation block elements in contact with the support block elements should have sufficient compressive stiffness and may be stiffer and stronger than other insulation block elements not in direct contact with the support system. The increase in load carrying capacity of the insulation block may for example be due to a higher density and increased fibre reinforcement in the insulation layer of the block element.

The present invention thus provides a thermally insulated cryogenic tank, typically a vacuum insulated tank, wherein the inner tank for fluid containment may have significant thermal shrinkage after cooling, and wherein the outer inner liner of the thermal insulation is comprised of interconnected insulation modules (referred to as insulation block elements) that locally follow the shrinkage of the main tank, wherein the tank system comprises an integrated or operatively connected support structure that is equally modularized by having a sufficient number of block element support sections in total such that the contact pressure for the insulation modules remains acceptable with respect to their load carrying capacity, and wherein each support section has the following characteristics:

the contact area of each block support element is sized and shaped to fit within the outer surface of the corresponding insulation module,

the contact zone of the block element against the insulation module may have a soft material layer with the ability to adapt to the internal tank itself variations and to local geometrical variations generally caused by thermal expansion or cooling of the insulation module for which the soft material layer provides support,

the contact support section is connected with a support system that connects the insulation tank with the base on which the tank system rests, and wherein the interconnected support structure of the support system can be moved with respect to the overall contraction of the insulation tank in a direction towards a point that is completely fixed with respect to the underlying base without producing unacceptable normal and tangential resistances on the contact surfaces against the corresponding insulation modules.

Brief Description of Drawings

Figure 1 shows in principle a cryogenic pressure vessel with a block insulation system.

Fig. 2a and 2b show in detail the gap between the insulating block element and the outer shell.

Fig. 3a and 3b show the insulating block element and deformation after cooling the inner vessel.

Fig. 4 shows details of the block element, soft layer and insulating block element design.

Fig. 5a, 5b and 5c show details of the overall thermal deformation as a function of position on the can.

Fig. 6a and 6b show the deformations in the block element.

Fig. 7 shows the outer shell of a tank in a support structure in the tank system of the invention.

Fig. 8a, 8b, 8c and 8d show embodiments of soft support layers between the bulk elements and tank insulating bulk elements or outer shell areas covering the insulating bulk elements in the tank system of the invention.

Fig. 9a and 9b show a tank system of the present invention lifted by a support structure.

Detailed Description

Figure 1 shows a cryogenic tank with vacuum insulation, wherein the vacuum layer consists of a porous insulation block covered by a gas tight, flexible corrugated skin. The figure may represent an application to which the present invention may be applied. 30 represents any type of container system such as a cylindrical, spherical, grid pressure vessel (lattice pressure vessel) or any type of pressurized or non-pressurized prismatic or other shaped container. The modular vacuum insulation system consists of an insulation block 31 covering the entire surface of the tank. There is a thin leak-proof membrane 32 with corrugations 33, the leak-proof membrane 32 covering the entire outer surface of the tank with the insulating blocks, forming an airtight outer shell. The corrugation 33 is an important part of the inventive concept, since the main tank 30 will shrink significantly when filled with a cryogenic fluid. It is also worth noting that the insulating blocks are separated by open spaces 34, the open spaces 34 serve two main purposes: (1) The open space prevents the insulation blocks from pressing against each other when the main tank is contracted by cooling, and (2) the open space serves as an air discharge passage during the vacuuming process. Obviously, the pattern of these gaps coincides with the pattern of insulating blocks. Fig. 1 also shows the cold liquid 35 in the tank and the top part 36 in gaseous form. There are also pipes 37 and 38, the pipes 37 and 38 enabling a controlled filling and draining of fluid from the outside to the outside. The pipe 39 represents the connection between the air discharge channel 34 in the insulator and the external vacuum pump system. The internal pressure within tank 30 corresponds to the vapor pressure, which in turn depends on the fill level and the actual fluid temperature. In addition, there is a gravitational pressure component and a dynamic pressure component. An important goal is to achieve the best possible thermal isolation to keep the temperature and pressure build-up within acceptable limits. The main purpose of vacuum insulation is thus to achieve the best possible thermal insulation.

The structural container 30 contracts while the membrane 32 maintains the temperature of the air or gas surrounding the exterior relatively unchanged. The thermal contraction of the strong and rigid inner can forces the insulator and membrane to squeeze together so that the corrugations 33 between the elements 31 will be compressed. Thus, primarily the corrugations compensate for the change in geometry of the rigid inner tank. Obviously, the support system directly connected to the surface of the flexible membrane will take into account the overall thermal shrinkage of the inner tank 30 as well as the local deformation. Furthermore, such a support system must not interfere with the corrugations themselves. Fig. 2a and 2b show two versions of the block vacuum insulation concept in more detail. 30 are the outer surfaces of the fluid container as described in fig. 1. Assuming that the inner tank 30 with fluid inside is significantly cooled, the tank surface will shrink accordingly in correspondence with the thermal properties of the tank material and the forced temperature decrease. In the presence of liquid hydrogen at-253 ℃ in the tank, typically for alloyed austenitic stainless steel, the sign of shrinkage is about 3mm to 6mm per meter length. The load carrying elements of the insulation system consist of porous or fibrous light-weight insulation blocks 31, the insulation blocks 31 being fixed to the surface of the container 30 by mechanical and/or glued attachment. The bulk material must be sufficiently open and porous so that air or gas initially trapped in the insulator can be completely evacuated as part of the evacuation process. The blocks are separated by an initial gap 34. The shape and width of these gaps should preferably be such that they do not close during cooling and thermal contraction of the fluid container 30 to avoid overlap, but rather remain open channels for achieving and maintaining a vacuum around the entire tank. The size and shape of these gaps therefore depend not only on how much the container is contracted, but also on the actual size of the block. Examples of block sizes may be 0.5m to 2.5m, while other block sizes may be possible. Typical thicknesses of the insulating blocks may be from 0.1m to 1m, although other thicknesses are also suitable. It should be noted that the insulating block is flexible and can accommodate the same shrinkage as the container at the tank surface, while the outer portion of the block remains fairly undeformed due to only minor or moderate thermal changes in the external ambient gas or air.

The requirement for achieving a vacuum is that the vacuum space is completely sealed and that the outer housing remains intact during operation without damage. This is achieved by having a sealed outer shell (membrane) on the outside of the insulating blocks which are able to conform to the overall thermal shrinkage of the inner vessel. The ripple across the open gap between the blocks is critical to handle can shrinkage. Fig. 2a shows the outward corrugation in more detail, while fig. 2b shows an alternative inward corrugation 40. Both solutions are fully applicable and function in essentially the same way during the shrinkage of the can. The membrane is also subjected to external pressure caused by atmospheric pressure on the outside and vacuum within the insulating layer; here an external pressure of about 1 bar or 0.1 MPa. In case 2a, pressure acts on the outward, arch geometry 33, which results in a membrane stress component in compression giving a small "push" across the gap. For case 2b, the difference is that pressure acts on the inward "hammock" type geometry 40, causing the film stress component in tension to give a small "pull" through the gap. Both of these principles work in practice. The advantage of the outward corrugation is that the necessary welding of the membrane portions becomes easier to achieve and easier than in the inward case. The inward corrugations require less space and are less susceptible to mechanical damage from external sources. The inward corrugations may also require additional grooves 41 to modify the geometry of the gaps between the blocks to provide room for the corrugations and thus avoid direct contact with the insulating blocks. In any case, for inward or outward corrugation, the external support system for such cans should also be modular accordingly and only come into contact with flat or curved membrane surfaces facing away from the corrugation zone.

Preferably, the curved or smooth corrugated portion of the outer shell (which portion covers the gap between the insulating block elements and absorbs shrinkage when the inner vessel is cooled and absorbs stretching when the inner vessel is heated) has a cosine-like shape as seen in cross section along the gap. At the position where the two gaps intersect, the shape of the curved portion is preferably a superimposed cosine-like shape. In some embodiments, other smooth, curved shape type of corrugation geometries may be applied.

Figure 3 shows the problem of heat shrinkage of the inner vessel in more detail. FIG. 3a shows a 3X 3 insulation block pattern before cooling of the main tankAn outside view of the surface cross section. The line 50 may be considered a system line marked on the surface of the inner container before cooling occurs. The distance between the system lines is a in one direction and b in the other direction. The figure also shows the film areas 51 between the corrugations and the corrugation pattern 52 between the blocks (inwardly or outwardly oriented) before cooling. The size of the contact area is c in one direction and d in the other direction. Thus, the span of the corrugations is e=a-c in one direction and f=b-d in the other direction. FIG. 5b shows the situation after thermal cooling, wherein the distance between the system lines 50 on the inner tank has been reduced to a _T And b _T . The actual shrinkage depends on the temperature change Δt after cooling of the can and the thermal expansion secant modulus α of the can, and therefore

a _T =a (1+αΔt), and b _T ＝b(1+αΔT) (1)

It should be noted that with respect to an initial temperature of 20 c before cooling, such as for example-273 c for liquid hydrogen, Δt is negative. The outer film does not undergo significant self-heat shrinkage because it is maintained at the current external temperature. This means that the thermal contraction of the inner vessel must be accommodated by mechanical contraction in the corrugated region shown shaded in the figure. Thus, the span e of the corrugated region after cooling _T And f _T The process is as follows:

e _T ＝a _T -c, and f _T ＝b _T –d (2)

The actual mechanical contraction to which the corrugations are subjected is:

Δe＝e _T -e=aαΔt, and Δf=f _T –f＝bαΔT (3)

The contraction caused by the corrugation is proportional to the distances a and b between the system lines 50. The dimensions of the corrugation spans e and f should be chosen in a mechanically feasible manner, which in turn depends mainly on the actual corrugation design. Choosing larger distances a and b means less waving and welding and cheaper solutions. Numerical simulations indicate that for the present invention, a distance between corrugations of about 2 meters is feasible; this is about ten times larger than the current corrugated design type shown in fig. 1. Represented by a and bThe side dimensions of a typical block size of (c) are preferably in the range of 0.25m to 2m, but smaller dimensions are also possible and larger dimensions are also possible, in particular for applications requiring lower requirements than LH 2. The respective gap sizes are preferably wide enough to always maintain an open gap, which means that the spans of the bent portions or gap sizes e and f are preferably larger than the respective strains Δe and Δf, wherein both Δe and Δf are negative. The gap g and the corrugation span are not necessarily the same. However, if g _a And g _b Representing an initial gap in two directions, the non-closed condition of the gap is:

g _a +Δe>0, and g _b +Δf>0 (4)

The increment is negative for both the curvature and its width.

Regarding the width of the curved portion and considering the absolute values of Δe and Δf, e is preferably at least 2 Δe, even more preferably at least 3 Δe or 5 Δe, but preferably not wider than 8 Δe or 10 Δe or 15 Δe. And as such, f is preferably at least 2 Δf, more preferably at least 3 Δf or 5 Δf, but preferably no wider than 8 Δf or 10 Δf or 15 Δf. The curved portions preferably have an initial height of at least 0.5 ae and 0.5 af, respectively, to ensure consistent bending direction. Since the outer shell will in fact be in a stationary state for several years, since the inner vessel will remain at a low temperature, there is no particular limitation on the minimum width or maximum width of the gap and/or the bent portion, since even a plastically strained bent portion or a very wide bent portion will be airtight. It is preferable to maintain an open gap in order to create a vacuum in the insulator and avoid plastic strain in the curved portion, while it is preferable to avoid a very wide gap in order to reduce the heat ingress due to radiation and to avoid questioning the robustness of the outer shell. For further details on the canister, reference is further made to parallel patent application NO 20200964 and to international patent application claiming priority thereto, the contents of which are incorporated herein by reference.

Fig. 3 illustrates the effect that thermal shrinkage may have on the support system. In case 3a the support is connected to only one module and the thermal effect will be limited to local movements caused by the whole tank shrinkage plus a possible slight change in the surface geometry of the curved contact surface. The moving part of the whole can be handled by the sliding mechanism of the support and the local effect by the flexible contact layer on the support. When the support is in contact with several block modules (e.g. patterns of 1 x 2, 1 x 3, 1 x 4, 2 x 2, 2 x 3 modules etc.), it can be seen that the system lines between adjacent contact areas will move closer to each other. This relative movement between the contact areas may be relatively small compared to the overall can shrinkage, and thus, as will be described below, may be handled by applying a flexible contact layer on the support surface.

Fig. 4 shows an embodiment of the invention for a support under a single block module 31. 60 is an intermediate, soft, contact zone layer, which may be made of rubber, polymer or other type of highly deformable material, which can be easily adapted to the exact geometry of the surface skin layer 32. Furthermore, as will be shown in fig. 8, it is possible to introduce a specific geometry for the layer, e.g. a specific geometry may reduce the stiffness of the layer and the restraining force in a specific direction. It is assumed that the contact layer contacts the surface skin layer at 61 without slipping. It is also assumed that the contact areas 62 of the contact layer against the support blocks 63 contact without slipping. The support blocks 63 may be made of laminated wood or plastic, which is commonly used to support cryogenic tanks, or even steel, as the purpose of the support blocks herein is primarily to support and not thermally isolate. The support blocks 63 may be held in a fixed position with surrounding "shoes" 64 or guided by guide rails 65 to move in the direction of overall contraction. In case sliding is required, it is important that the contact surface 66 between the block 63 and the holding means 64 has as low friction as possible. The holding means is attached to the base 67, e.g. the inner deck of the vessel, by a suitable method, such as welding. It should also be noted that the provision may require that the height of the open space 68 between the exterior surface of the tank 32 and the base 67 be large enough for access for inspection, which in fact will determine the height of the support block 63.

One of the suitable materials for the insulating material in the block element 31 isReinforced polyurethane foam R-PUF. The strength of such materials varies between 1MPa and 1.5MPa, typical compressive strength, depending on density, reinforcement and manufacturer. Assuming a significant safety factor is applied, this causes an allowable compressive stress of 0.4MPa or 40 tons/m ³ . Further assume that the support is considered for a storage volume of 10000m ³ Particularly large tanks for liquid hydrogen LH 2. A typical weight of such a tank, assuming a grid pressure vessel and filled with LH2 cargo, may be about 800 tons. Further assume that the tank is on the vessel, wherein the additional inertial forces generated by the vessel motion bring the total weight carried by the support to 1200 tons. This in turn means that a contact surface with the insulating block of about 30m is required ³ So as to transfer the total load to the support. Further assume that the contact surface with the individual blocks is 3m ³ . This means that only supports under 10 element blocks are needed to carry 10000m ³ LH2 tanks and their cargo. The purpose of this example of calculation is to show that it is highly realistic to implement the invention under practical conditions. Obviously, other numbers are applicable to other applications.

Fig. 5 shows a support for a competitive tank according to the invention. Fig. 5a shows the short side of the insulation can (end view), fig. 5b shows the long side (side view), and fig. 5c shows the can from below (bottom view). The situation shown is particularly applicable to tanks on vessels, floating offshore installations or other applications, where the tanks and support system are subjected to side loads in addition to gravity. Obviously, most land-based tanks may not require lateral support except when potentially subjected to seismic loads. The tank size in the figure is moderate; this is chosen to show the principle of the support without unnecessary complexity. For example, assuming each bulk insulator has a size of about 2m, it is straightforward to estimate the size of this particular example. Furthermore, the tank appears to be a so-called "flat wall" grid pressure vessel, in which all supporting sides are flat, the insulating blocks 70 are flat, and the side corners are covered by corner cylindrical block elements 71 and turning corners of block elements 72 having a double curved geometry. Reference numeral 73 denotes support blocks of the type shown in fig. 4, which are in direct contact with the planar surface of the tank. It is important that the support contact surface does not contact the corrugation 33 shown in fig. 1, 2 and 3 and damages the corrugation 33. It should also be noted that there should be no sliding at the contact surface 61 between the insulating block and the support block.

Cryogenic tanks with or without internal pressure maintain significant heat shrinkage, for example up to about 6mm per meter for LH2 made of cryogenic steel. This shrinkage should be made possible by the design of the support block, which allows sliding at the outward surface of the block (see 66 in fig. 4) or possibly a sliding layer within the block itself (as shown in fig. 6). Obviously, the tank support should provide constraints on the overall sliding and rotation of the entire tank. In fig. 5c, the midpoint 74 of the underside of the tank is selected as the fixed point and the support block remains non-slip. The arrowed dashed line 75 indicates the direction in which the movement of the contact surface 64 will be towards the fixed datum 74. Thus, midline support blocks such as 76 and 77 may be guided in a direction toward midpoint 74 in a simple manner (e.g., sliding surface 90 having grooves 91 in the support block, see both views in fig. 6a and 6 b). The inserted steel plate, which is directed in the sliding direction in the sliding plane, may perform a similar function. Corner support blocks 78 may also be directed in the direction of dashed line 75, or they may provide vertical support without lateral restraint.

The support blocks 79 on the sides in fig. 5 are used to provide lateral support for tanks placed on a mobile platform (e.g., a ship) to be exposed to additional lateral forces from tipping, wave motion, and possibly unexpected loads. As indicated by the contracted dashed lines and arrows in fig. 5a and 5b, the tank surfaces of the tank against the support blocks may not only move parallel to the surface, but they may also have an inward component of motion normal to the surface itself. Sliding parallel to the surface can be handled in the same way as described for the support under the tank. However, the movement component resulting from the contraction should be handled in a different way to avoid that the gap opens between the tank and the lateral support blocks. For this purpose, several methods are possible, such as mechanical or hydraulic means to compensate for the normal shrinkage movement of the tank after cooling. Alternatively, the side supports may have inclined inner sliding surfaces corresponding to the direction of contraction corresponding to the dashed lines in fig. 5. The skewed sliding surface 92 in the support block is shown in fig. 6c before retraction and in fig. 6d after retraction. The method for compensating the shrinking motion illustrates the general feasibility of the block support method of the invention.

Other types of support devices that hold the tank against lateral forces and roll motions are commonly used for insulation tanks on ships, as is well known. Such supports are typically mounted in a longitudinal plane above a fixed datum point and on top of the tank using a combination of steel supports, thermally insulated wooden blocks and sliding surfaces. Obviously, such a conventional anti-roll support may be used as an alternative to the lateral support shown at 79 in fig. 5. However, this can present serious problems, as conventional anti-roll supports have portions that must be welded to the inner tank and penetrate the surrounding insulation. The vacuum insulation relies entirely on a sealed outer shell, represented here by an outer corrugated skin 32. Due to significant thermal shrinkage and repeated roll motions on the vessel, if such anti-roll devices are applied to large tanks with vacuum insulation, it may be difficult to avoid cracking of the outer hull area near the support and to maintain air tightness. The lateral support system proposed by the present invention is therefore a preferred alternative.

Obviously, the need for lateral supports depends not only on the movement and loading conditions of the base, but also on the geometry of the tank itself, in particular the shape of the tank bottom and the aspect ratio of the tank. Grid pressure vessels with medium height and flat bottom may not require lateral supports, as lateral and overturning forces may be handled by the support system below the tank.

The invention can be easily implemented on various other types of tank supports, such as saddle supports for most cylindrical tanks and round-edged grid pressure vessels. Fig. 7 shows a schematic outline of a saddle support 92 for a tank with a vacuum bulk insulator with an insulating bulk element skin 32 (part of the outer shell over the insulating bulk element), the insulating bulk element skin 32 having outward corrugations 33, see also fig. 2. The support blocks 93 resting on the saddle support have a cylindrical surface conforming to the geometry of the skin layer and soft elastic contact layer. Small changes in geometry and radius caused by thermal shrinkage are easily handled by the deformability of the contact layer. The large displacement caused by thermal contraction in the circumferential direction of the cylindrical geometry can be handled by a curved version of the sliding block shown in fig. 6a and 6 b. The large constricting movement in the longitudinal direction of the cylindrical form can similarly be handled by sliding the contact surface under the carriage, generally as shown in fig. 5.

Fig. 8 shows some alternative solutions that provide additional flexibility of the contact layer 32 and can be used for flat and curved block supports. One characteristic of elastomers is that they generally have a low modulus of elasticity (young's modulus E) and a high deformability, while they also have a high transverse strain ratio (poisson's ratio v) that can approach 0.5, which makes the material almost incompressible (very stiff in volume). Therefore, the rubber layer constrained and pressed between two surfaces of the same shape becomes extremely rigid in the pressure direction. This may be a concern for the use of such materials in the present invention, as it is desirable that the intermediate contact layer should be able to accommodate uneven and shape-changing surfaces, and preferably also allow some local lateral movement consistent with local thermal contraction. Fortunately, it is quite easy to adjust the stiffness properties of the elastomeric layer by adding geometry. Fig. 8 presents some ways of adapting to the application in the support system of the invention. In fig. 8a, a thick elastomeric sheet 100 (corresponding to 60 in the previous figures) is cast and perforated with a regular or staggered pattern of perforations 101. The material properties, the thickness of the plate, the diameter of the holes and the distance between the holes determine the normal stiffness and the lateral shear stiffness of the layer, from which the optimal stiffness properties in three spatial directions can be derived. Fig. 8b shows a soft elastomer layer 60 consisting of a plate 102 facing the tank, the plate 102 having cylindrical posts 103 in contact with the support blocks as shown in fig. 5, 6 and 7. The diameter and length of the post determine the normal stiffness and lateral stiffness. It should be noted that this type of original flat plate can be easily bent into a cylindrical shape according to the need of the curved surface of the insulation tank. Fig. 8c shows a slightly modified version, wherein each cylindrical post 104 is hollow. Obviously, such a column may provide softer properties of the intermediate support layer than in the former case. Fig. 8d differs in that different lateral stiffness is provided in both directions of the contact plane. 104 represent ribs or webs that provide significant stiffness in the normal and longitudinal directions of the web (shown here as the y and z directions), while the stiffness in the x direction normal to the web may be very low. Obviously, the actual stiffness depends on the height, width and distance of the sheet. The significance of this version is that it can be very compliant and allows for significant thermally induced displacement in the x-direction while providing sufficient stiffness and strength in the other two directions. Depending on the size of the tank and support and the actual thermal shrinkage of the tank, as shown in fig. 8, the use of a softened intermediate layer may be sufficient to provide lateral displacement in a single support or row of block supports (as shown in fig. 5) or saddle supports (as shown in fig. 7). This means that heat shrinkage can be handled in some cases by soft contact layers, rather than by providing sliding of the support itself.

The present invention provides significant advantages with respect to the manufacture, transportation, handling and installation of the vacuum heat insulated cans mentioned herein. Typically, the main vessel tank, the inner tank (preferably the pressure tank), is produced in a dedicated manufacturing facility or building site. A common procedure is to lift the tank by means of primary lifting lugs welded to the tank surface, transport the tank on intermediate supports on a barge or other type of vehicle, and then put the tank down at the final location of the tank (e.g. in a ship) on a permanent support system. In addition to the case of conventional double shell vacuum tanks with integrated rigid outer shells, the application of thermal insulation to the cryogenic tank is typically performed after the tank is finally placed. There are several complications associated with this, particularly in connection with lifting, installation, and overall sealing of tanks and pipes at the installation site. Alternatively, the invention allows for the complete completion of tanks with complete vacuum insulation and support at a particular manufacturing facility.

Fig. 9 shows this approach, which easily implies a significant cost and time saving and better production quality. Fig. 9a shows a situation similar to that shown in fig. 5, which may be generally a grid pressure vessel with flat sides and a bulk vacuum insulator. The full tank 110 stands on a block support 63 with a soft layer 60 supporting the surface skin 32 of the tank, see also fig. 4. The block supports are mounted on a common support structure 111, the common support structure 111 together with the block supports constituting the final support system for this section of the tank. It should be noted that 111 extends beyond the sides of the tank so that there is room for the hoisting cable 112. Fig. 5 shows an example of such a support with 3 rows. Having a common support structure 110 facilitates lifting, transporting and installing the complete tank in an efficient manner, as lifting cables, chains or straps 112 may be easily attached to the support structure 111. The figure also shows an intermediate lifting beam or frame-like suspension structure 113, to which suspension structure 113 lifting cables are attached. The lifting frame 113 is similarly connected with lifting cables 114 such that these lifting cables are assembled to a common lifting point or beam 115, which common lifting point or beam 115 in turn is connected to a common lifting point 117 for the crane by cables 116. This is an example of a fully viable vacuum insulated tank for a prefabricated belt support system and installed in an end use position. Fig. 9b shows a lifting operation similar to the former case, the only difference being that the support structure is saddle-shaped. Obviously, the specific lifting device may in fact be different from that shown in fig. 9, depending on the available lifting and handling capacity of the apparatus and regulatory requirements.

A canister for LH2 with a vacuum insulator within the hermetic outer shell is the most challenging embodiment, and thus the case of a canister for LH2 is illustrated in detail. However, the benefits of the present invention will also exist for less demanding tank embodiments and uses, for which reason the scope of protection provided also requires a simpler tank system. The disclosure for the simpler tank system and use is the same as that for the LH2 tank, however, some features or steps may be omitted as the case may be.

Claims

1. An insulated tank system, comprising: an inner tank; a thermal insulator external to the inner tank; an inlet and outlet or a combined inlet and outlet from the outside of the tank to the inside of the inner tank for filling and emptying of the fluid, wherein the inner tank contains the fluid when installed and in operation,

characterized in that the tank system further comprises:

thermal insulation in the form of insulation block elements arranged side by side on the outside on the inner vessel, with a gap between the insulation block elements at least on the outside of the insulation block elements, wherein the vessel system further comprises a support structure comprising one or more block elements, wherein each block element faces and is in contact with an insulation block element directly or via one or more intermediate layers, wherein at least some block elements preferably comprise a sliding layer, wherein the support structure comprises a structure for lifting the vessel by the support structure, wherein the vessel can be lifted and handled by loading only the outer insulation block elements facing the block elements without directly loading the inner vessel, and wherein thermal contraction or expansion is absorbed by sliding and by the gap between the block insulation elements.

2. The insulation can system of claim 1, further comprising an outer shell that is airtight and covers an external insulation, wherein the portion of the outer shell that covers an insulation block element has a shape that matches the external shape of a corresponding insulation block element and is fastened to a corresponding insulation block element, and the portion of the outer shell that covers the gap between the insulation block elements has a curved shape, preferably a cosine shape, seen along the corresponding gap and is a superimposed cosine shape where the two gaps intersect, allowing thermal contraction or expansion of the can to be compensated at the outer shell by local bending of the curved portion across the gap.

3. The insulated tank system of claim 2 further comprising a coupler with an opening through the outer housing to the insulation for coupling a vacuum pump to the insulation for evacuating gas from the insulation so that there is a vacuum in the insulation between the outer housing and the inner tank when the tank is in operation.

4. An insulated tank system according to any one of claims 1-3, comprising a layer of elastomeric material between the bulk element and the bulk insulated element in order to achieve smooth force transmission and geometric compatibility during operation.

5. The insulated tank system of any of claims 1-4, comprising a block element that is laterally slidable to compensate for overall thermal deformation of the tank without any sliding at a contact surface between the outer housing and the block element.

6. The insulated tank system of any one of claims 1-5, comprising a block element on a side of the tank to ensure stability of the tank when subjected to static and/or dynamic motion and inertial forces.

7. Insulation tank system according to any of claims 1-6, comprising mechanical and/or hydraulic means and/or a block element with a sliding layer, so as to ensure contact between the outer housing and the block element.

8. The insulated tank system of any of claims 1-7, comprising a support structure having a frame or beam with a lifting point at a position laterally protruding from below the tank when the tank is placed on a base, thereby facilitating lifting and transport of the tank without requiring a structure directly connected to the inner tank.

9. The insulated tank system of any of claims 1-8, wherein the number of block elements is adapted to ensure that stresses on the insulation and the outer shell are below acceptable limits specified by regulations and regulations in the presence of all the time.

10. A method of manufacturing a tank according to any one of claims 1-9, characterized in that, at the place of manufacture or in a ship,

arranging insulating block elements side by side on the inner tank, with gaps between the insulating block elements,

manufacturing or providing an inlet and an outlet, said inlet and said outlet being as a combined structure or separate structures,

a hermetically sealed outer housing structure is manufactured or provided that, when a vacuum pump is included in an embodiment of the canister, has a coupling for the vacuum pump,

at least one support structure is manufactured or provided for operative construction or connection to the tank, wherein the support structure comprises one or more block elements, each block element having a shape matching a specific insulation block element, wherein the support structure further comprises a mechanical structure for lifting and transporting the tank without any lifting attachment penetrating the insulation layer for direct connection with the inner tank.

11. A method according to claim 10 or 11, wherein the tank is manufactured in multiple parts and assembled at the manufacturing site or in a vessel or on a floating platform.

12. A method according to claim 10, 11 or 12, wherein the tank and vacuum insulation when present are subjected to leak testing at the manufacturing site prior to transportation and installation at their final destination.